中国东北部地区金矿成矿系统分析

本文简要分析了东北地区区域成矿地质背景.从金成矿物质来源的同一性和继承性出发划分出3个金成矿系统:(1)变质岩金成矿系统,以变质岩含金建造为物源基础,形成了多种矿床类型组合;(2)中(新)生代陆相火山热液金成矿系统,矿床产出于中(新)生代火山岩系分布区,成矿物质主要源于火山岩系;(3)第四纪砂金成矿系统.     

划分金矿化集中区的基本准则

在划分和确认金矿化集中区时需研究的重要问题之一就是集中区的范围和界限.在现有的技术经济条件下,确定金矿化集中区的范围和边界应当以已知金矿床（点）的分布范围作为直观标志,以金的地球化学块体和各类含金建造的空间分布作为划分的基础,以控制各类含金建造和与金成矿关系密切的构造-岩浆活动等成矿要素的区域构造带或构造界面作为金矿化集中区的边界.利用上述准则确认了北山金矿化集中区.     

Distribution, partitioning and fluxes of dissolved and particulate organic C, N and P in the eastern North Pacific and Southern Oceans

Concurrent distributions of dissolved and suspended particulate organic carbon (DOC and POC_susp), nitrogen (DON and PON_susp) and phosphorus (DOP and POP_susp), and of suspended particulate inorganic phosphorus (PIP_susp), are presented for the open ocean water column. Samples were collected along a three-station transect from the upper continental slope to the abyssal plain in the eastern North Pacific and from a single station in the Southern Ocean. The elemental composition of surface sedimentary organic matter (SOM) was also measured at each location, and sinking particulate organic matter (POM_sink) was measured with moored sediment traps over a 110-d period at the abyssal site in the eastern North Pacific only. In addition to elemental compositions, C : N, C : P and N : P ratios were also calculated. Surface and deep ocean concentrations of dissolved organic matter (DOM) and inorganic nutrients between the two sites displayed distinct differences, although suspended POM (POM_susp) concentrations were similar. Concentrations of DOM and POM_susp displayed unique C, N and P distributions, with POM_susp concentrations generally about 1–2 orders of magnitude less than the corresponding DOM concentrations. These differences were likely influenced by different biogeochemical factors: whereas the dissolved constituents may have been influenced more by the physical regime of the study site, suspended particulate matter may have been controlled to a greater extent by biological and chemical alteration. Up to 80% of total particulate P in POM_susp, POM_sink and SOM consisted of PIP. For all organic matter pools measured, elemental ratios reveal that organic P is preferentially remineralized over organic C and organic N at both sites. Increases in C : P and N : P ratios with depth were also observed for DOM at both sites, suggesting that DOP is also preferentially degraded over C and N as a function of depth. A simple one-dimensional vertical eddy diffusion model was applied to estimate the contributions of dissolved and suspended particulate organic C, N and P fluxes from the upper mixed layer into the permanent thermocline. Estimated vertical DOM fluxes were 28–63% of the total organic matter fluxes; POM_susp and POM_sink fluxes were 8–20 and 28–52% of the total.     

粘弹介质本构理论讨论

阐述了建立物质本构关系时应满足的基本公理,较详细地推导了各种类型粘弹性物质的本构关系,论述了变率理论与泛函数论之间的关系,推导了对于粘弹性问题求解具有实用意义的对应定理,并以简单的例子说明对应定理的应用。     

一种基于实体匹配的面要素无缝拼接方法及精度分析

基础地理信息数据通常是分幅、分层记录和存储的,分幅采集和处理过程中地理实体可能会在图幅边界产生缝隙。本文结合地图拼接理论,提出了一种兼顾几何关系和属性特征的面状地理要素无缝拼接的方法,并利用ArcGIS Engine提供的功能,在Microsoft VisualStudio 2008的开发环境下实现了这种方法。实验证明,该方法有效地实现了面状地理实体的物理无缝和逻辑无缝,是切实可行的。     

一种基于分块的分形图像压缩方法

分形编码具有高压缩比的特点,但在编码过程中其匹配搜索时间开销巨大.提出一种基于分块的分形图像压缩方法:依据人眼视觉特性在PSNR变化不大的情况下,图像主观质量感受不明显的特点,将图像在空域分割为若干相对较小的块,对感兴趣区可采取一分为四的方法进一步减小块的大小,然后对每个块分别进行分形编码,并重构.结果表明,在PSNR略有降低的情况下,编码的匹配搜索时间大幅减少,同时重构图像的主观质量并没有明显降低.     

中国新近纪构造-地层区划及地层格架

新近纪是中国地貌地形和气候环境格局最终奠定的关键时期,如青藏高原强烈抬升和现代高原地貌最终成型、中国南海海盆扩张结束、东亚现今大型水系格局最终建立、中国西高东低的地势最终确立以及东亚季风系统开始形成并逐渐增强.通过对中国新近纪大地构造、沉积盆地(群)、火山岩、隆起带和大型变形构造等的综合研究,共厘定一级构造-地层单元(...     

Climate change regionalization in China(1961–2010)

Since climatic condition is the important foundation for human subsistence and development and the key factor in sustainable development of economy and society, climate change has been a global issue attracting great attentions of politicians, scientists, governments, and the public alike throughout the world. Existing climate regionalization in China aims to characterize the regional differences in climate based on years of the mean value of different climate indexes. However, with the accelerating climate change nowadays, existing climate regionalization cannot represent the regional difference of climate change, nor can it reflect the disasters and environmental risks incurred from climate changes. This paper utilizes the tendency value and fluctuation value of temperature and precipitation from 1961 to 2010 to identify the climate change quantitatively, and completes the climate change regionalization in China(1961–2010) with county administrative regionalization as the unit in combination with China's terrain feature. Level-I regionalization divides China's climate change(1961–2010) into five tendency zones based on the tendency of temperature and precipitation, which are respectively Northeast China-North China warm-dry trend zone, East China-Central China wet-warm trend zone, Southwest China-South China dry-warm trend zone, Southeast Tibet-Southwest China wet-warm trend zone, and Northwest China-Qinghai-Tibet Plateau warm-wet trend zone; level-II regionalization refers to fourteen fluctuation regions based on level-I regionalization according to the fluctuation of temperature and precipitation.     

西昆仑早古生代岩浆弧大同岩体中埃达克质岩石的成因及地质意义

大同岩体位于西昆仑柯冈-库地-其曼于特和麻扎-康西瓦两条蛇绿混杂岩带之间。为进一步了解西昆仑早古生代岩浆弧中某些具体岩石类型、岩浆产生机理、地质意义及成因联系,本文从岩相学、主微量元素地球化学、锆石U-Pb年龄和Hf同位素等方面,对大同岩体中和外围新发现的埃达克质岩石进行了研究。埃达克质岩石由石英二长花岗岩和黑云母二长花岗岩两种岩性组成,呈独立的岩体和大同主岩体中的脉体两种产状,高硅(w(SiO₂)≥60.34%)、高铝(w(Al₂O₃)≥14.73%)、富碱(w(K₂O+Na₂O)≥6.40%)、低镁(w(MgO)≤2.35%),以及高锶(w(Sr)≥504×10^-6)、低钇(w(Y)≤17.20×10^-6)和高Sr/Y(平均为70.88),富集轻稀土元素和大离子亲石元素,亏损重稀土元素和高场强元素,不同程度负Eu异常及Ta、Nb、P和Ti亏损。锆石U-Pb测年显示,埃达克质岩石年龄为(443.6±1.4)~(462.0±1.0)Ma,与大同主岩体的形成年龄相当。锆石ε_Hf(t)为-7.28~4.56(平均-0.84),我们认为埃达克质岩石是由原特提斯洋洋壳及部分洋壳之上的陆源沉积物向南俯冲过程中,发生部分熔融形成的熔体上升过程中与地幔楔橄榄岩反应,最后定位于地壳浅层的结果。通过与大同岩体主岩体对比,对早古生代岩浆弧的形成和演化有了更深入的了解。     

盾牌座δ型变星4CVn的多重非径向脉动振幅变化

对非径向脉动δＳｃｕｔｉ（盾牌座δ）型变星４ＣＶｎ的最新光电测光观测，证实了其振幅和周期的长期缓慢变化．两种多重频率分析方法都一致确认出已知７个频率中的５个（ｆ１，ｆ２，ｆ３，ｆ５，ｆ７）．观测还发现三个可疑频率．目前主频的振幅和十几年前的一样，基本保持不变，可能正处于向最大振幅变化的增加阶段或者处于刚过极大的下降段．其它四个频率的振幅都不同程度地变大．ｆ２，ｆ３和ｆ５的振幅增幅分别为６３％，２５％和１２０％，尤其是ｆ７，从上次的０变为０．００９ｍａｇ．频率分析显示除主频ｆ１几乎未变外，其它频率缓慢变化：ｆ２和ｆ７约减小０．０８％；ｆ３减小０．１４％；ｆ５增加０．０３％．用Ｂｌａｚｈｋｏ效应和不同非径向脉动模式之间的共振解释振幅和周期变化的合理性，尚需进一步从观测上检验．